Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a687e99f2daf85…

MALICIOUS

PDF

83.8 KB Created: 2021-09-03 18:48:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c453b3a930446e675db3f2faa83751bc SHA-1: 46083ce1990621611654d8b71c8833b9f59e650d SHA-256: 81a687e99f2daf854d72c8411fc0bb31ef6a0d3e65f96165d563f359c4d57818
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code within documents. The file also exhibits characteristics of a link farm, with numerous URLs pointing to compromised websites and disposable hosting, suggesting an attempt to redirect users to phishing or malware download sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or trojan distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://allytemp.ru/uplcv?utm_term=apa+citation+style+manual PDF link annotation
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/d304e066803432cbf6163c748870ba7b/zebusanudezedemalesof.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e3a61508597---noveparut.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/fewijajikoposajowavi.pdfIn PDF document text
    • http://royalwedding.jp/images/blog//file/2551835533.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a3c478bcf7---jenowowutogatibek.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a57831c3148---rewufemewutikigamat.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608a6042423c8---rotitemulojogemuj.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/texuzunimopebev.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609bfb380e59b---bavel.pdfIn PDF document text
    • http://humanlitech.com/files/files/9418373903.pdfIn PDF document text
    • https://otartufo.com/ckfinder/tartufofiles/files/xexarovodewa.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/d3fba0dab400dc7d9cd1ff8587560939/58415585592.pdfIn PDF document text
    • http://upsshop.ru/ckfinder/userfiles/files/14534485334.pdfIn PDF document text
    • https://vietnamairlinescorp.org/js/ckfinder/userfiles/files/78304313515.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/gibilegofiwi.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/15332a4c1a2744c4349c7752a43a75a7/golip.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/xowanonerefawivenunulasup.pdfIn PDF document text
    • http://geodez.com/pliki/file/27884562034.pdfIn PDF document text
    • http://videofilm-tv.ru/content/File/57619548327.pdfIn PDF document text
    • http://stylekd.ru/files/77054191033.pdfIn PDF document text
    • https://studiovizia.com/webroot/img/content/files/39948245452.pdfIn PDF document text
    • http://lblussana.it/images/file/buruse.pdfIn PDF document text
    • https://celebicatering.com/upload/ckfinder/files/jefagexotewelogonulowut.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c325549331c---kigapujidarugoxebifatix.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE9 17616 bytes
SHA-256: cc7221644f6d5a0dd19db4e057ea0fdf289a73ca5ce6fc6b4d83bb8ec35d1342
font_02_sfnt_off00012899.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12899 10632 bytes
SHA-256: 59ada2f10138d72c73af92761ce102d9fa7abdcec17fe48d6aa0fe1a0973069e